问访问Highcharts工具提示中的下一个元素名称

EN

 series: [{ name: 'weight', data: [50, 48, 80, 70]}, 
          { name: 'height',data: [5.8, 5.1, 6.1, 6.0]}
         ]


   tooltip: {
               formatter: function(){
        return this.series.name;//i want to return here next elements name also is there any way
       }
         }